Wrong fuel? Help

[Jeremy Reuwer]

Hey all, maybe I'm posting this in the wrong section but my dumbass friend put in two gallons of 87 octane when I usually put in the specified 91 Oct that my 01 Cobra drinks

Will knock sensors catch this? How badly will it harm the engine? Any tips or advice to avoid knocking?

Thanks

 

[railroad]

Buy either 100 octane or a can of Torco and add to the tank. 2 Gallons of 87 in a full tank of 91 can be blended up.
If the car is a track car, pump it out and replace.

 

[Jeremy Reuwer]

Buy either 100 octane or a can of Torco and add to the tank. 2 Gallons of 87 in a full tank of 91 can be blended up.
If the car is a track car, pump it out and replace.

unfortunately no such things are easily available in the CARB state of California.
I think the safest thing to do is to drive like a granny, and put in more 91 every qurter of a tank exhausted